class City {
    cName: string;
    cLevel: number;
    constructor(cName1: string, cLevel1: number) {
        this.cName = cName1;
        this.cLevel = cLevel1;
    }

    about() {
        console.log(`${this.cName}是${this.cLevel}级城市`);
    }

}

let city1 = new City("苏州", 1);
console.log(city1.cName);
city1.about()
